The BBC director-general, Mark Thompson, has admitted the broadcaster does not have enough older female newsreaders and presenters

The BBC director-general, Mark Thompson, has admitted the broadcaster does not have enough older female newsreaders and presenters. He said the corporation had a case to answer over the lack of older women in key news and current affairs presenting roles.

He acknowledged that the landmark age-discrimination employment tribunal brought by ex-Countryfile presenter Miriam O'Reilly, 54, had been an important wake-up"call for the BBC.

In recent years, the BBC has come under criticism for perceived ageism and sexism in its handling of senior female presenters including O'Reilly, newsreader Moira Stuart and former Strictly Come Dancing judge Arlene Phillips.

In an article for the Daily Mail, Thompson writes that there are too few women among the BBC's most senior on-air specialist journalists, particluarly those who conducted the big political interviews.

While he said there had been a revolution in the number of older women in leadership roles at the BBC, he said this had not been reflected at the same rate or scale of change on screen.

Thompson said a thoughtful critic of the BBC might observe two failures.

"First, that there is an underlying problem, that – whatever the individual success stories – there are manifestly too few older women broadcasting on the BBC, especially in iconic roles and on iconic topical programmes," he said.

"Second, that as the national broadcaster and one which is paid for by the public, the BBC is in a different class from everyone else, and that the public have every right to expect it to deliver to a higher standard of fairness and open-mindedness in its treatment both of its broadcasters and its audiences."

Thompson also notes that a survey, called Serving All Ages, found that a significant minority of men and women throught that older women were invisible on television. The report revealed that more than a third of women over 55 said there were not enough of their contemporaries on screen.

"That perception, and the reality behind it, is what we have to change," Thompson writes.

The BBC chief said the broadcaster must develop and cherish its many outstanding female staff and ensure that they know age will not be a bar to their future employment at the corporation.